Apparatus for drafting textile fibres



Nov. 13, 1962 G. H. AMBLER APPARATUS FOR DRAFTING TEXTILE FIBRES Filed001;. 24, 1960 United States Patent Ofifice 3,063,102 APPARATUS FORDRAFTING TEXTILE FIBRES Geoffrey Hill Ambler, Illtley, England, assignorto Ambier Superdraft Limited, Ilkley, England, a British company FiledOct. 24, 1960, Ser. No. 64,415 Claims priority, application GreatBritain Nov. 27, 1959 6 Claims. (Cl. 19-287) This invention relates toapparatus for drafting textile fibres in the form of rovings or thelike, the apparatus being of the kind in which an intermediate unit ismounted on the apparatus between feed and drafting rollers for slidablemovement in a direction transverse to that of movement of the roving orthe like, and means are provided for reciprocating the unit so as totraverse the roving or the like passing through the unit across thedrafting rollers, the purpose of such traversing movement, in general,being to avoid localised wear of the drafting rollers as would occur ifthe yarn emerging from the nip of such rollers due to the draftingaction were continuously to engage the same circumferential line on therollers, one of which is usually formed from non-metallic material,e.g., a granulated cork compound, and is thus particularly prone to suchlocalised wear. Such wear is generally known as roller nicking, andinterferes with the drafting action, particularly when drafting to ahigh degree, e.g., at drafts of 50, 100 or more, when precise grabbingaction of the rollers on the fibres is necessary. Consequently, it hasbeen found necessary to replace or re-grind the non-metallic draftingrollers at frequent intervals to ensure efficient drafting action, andthis is generally inconvenient and expensive.

Although such Wear is reduced considerably by the traversing movementreferred to above, it still persists at the circumferential lines on theroller surface corresponding to the limits of the traversing movement,because of the short dwell at each end of the movement occasioned by thetaking up of the inevitable working clearances necessary in thetraversing mechanism, such clearances becoming greater as normal Weartakes place.

An object of the invention is to provide a traversing mechanism whichreduces still further the roller nicking arising from such dwell at thelimits of the traversing movement.

According to the present invention, there is provided a draftingapparatus of the kind referred to, wherein the taversing mechanismcomprises a stationary internal gear secured to the drafting apparatus,a driving shaft arranged co-axially with the internal gear, a firsteccentric secured to the driving shaft, an external gear freely mountedon the first eccentric and adapted to mesh with the internal gear, and asecond eccentric or a cam secured to the external gear and adapted toengage an abutment connected to the intermediate unit.

By these means, upon rotation of the driving shaft, the axis of thepinion is caused to gyrate about the axis of the driving shaft, while atthe same time, the pinion rolls around the internal gear and is drivenby that gear to cause rotation of the second eccentric. Such motionsproduce a reciprocation of the intermediate unit that varies inamplitude so that the point of reversal of the traversing yarn on thedrafting roller surfaces varies from one stroke to another of thetraversing mechanism, and the Wear thus takes place at a number ofdifferent points over the roller surface. It is preferable that theeccentricities of the two eccentrics are slightly different inmagnitude.

It is, of course, preferable that the reversal should take place at asmany different points on the roller surface as possible before takingplace at any point a second time, thus spreading the wear as evenly aspossible over the 3,063,192 Patented Nov. 13., T9 62 width of thedrafting rollers. Though considerations of space, complication of designand cost, limit to some extent the degree of variation to be obtained,one example of a traversing mechanism according to the invention thathas been found to give satisfactory results both as regards the qualityof drafting and the useful life of the drafting rollers will now bedescribed in greater detail with reference to the accompanyingdiagrammatic drawings, in which FIGURE 1 is a sectional elevation ofpart of a drafting apparatus,

FIGURE 2 is a view of part of the apparatus shown in FIGURE 1 as seen inthe direction of the arrow in FIG- URE 1 and drawn to a somewhat largerscale than FIG- URE 1, and

FIGURE 3 is a diagram illustrating the trace pattern of the traversingyarn.

A roving 11 is passed through the nip of a pair of feed rollers 12 and13 and through a roving guide 14 to the nip of a pair of intermediaterollers 16 and 17, and from there through a channel-shaped member 18 tothe nip of a pair of drafting rollers 19 and 21 from which it passes inthe form of a yarn 22 to the bobbin of a spinning device of knownconstruction.

The roving guide 14, intermediate rollers 16 and 17, channel-shapedmember 18 and gearing for driving the intermediate rollers are mountedin an intermediate unit indicated generally in FIGURE 1 by referencenumeral 24.

The main framework 26 of the unit 24 is formed with a semi-circularbearing surface 27 arranged to rest on the upper surface of a bearingmember 28 forming part of the drafting apparatus, the bearing memberbeing secured to a support 29. The unit 24 is attached to a pair ofsupports 31 forming part of a saddle member 32 by means of a pair ofpins 33 slidably mounted in the framework 26 and arranged to engage acorresponding pair of holes in the supports 31. The pins 33 are actuatedby a pair of leaf-spring members 34 secured to the framework 26, the

pins 33 being reduced at 36 to form a pair of spaced shoulders, thereduced portions 36 passing through suitable key-hole slots (not shown)in the leaf-spring members 34.

The saddle member 32 is one of a series each supporting a unit 24, asindicated in FIGURE 2, and each saddle member 32 is mounted on anextension 37 of the corresponding bearing member 28 (one of which isprovided for each unit) by means of a pair of rods 38 and 39, the rods38 being secured to their respective saddle members while the rod 39 iscommon to the series of saddle members. The rods 38 and 39 are slidablymounted in the extensions 37 and the saddle members are positioned bymeans of a series of pins 41 projecting from the rod 39.

The saddles 32 are traversed by the rod 39 on which is secured by meansof a pair of depending brackets 42 a traversing frame 43.

A shaft 47 is rotatably mounted in a housing 48 secured to the support29. Secured to the shaft 47 is a wormwheel 49 arranged in mesh with aworm 51 secured to a shaft 52 rotatably mounted in the end bearingmembers 28 of a series and constituting the common driving shaft for theseries of units.

The shaft 47 is formed with an eccentric 46 on which is freely mountedan external gear 53 arranged in mesh with an internal gear 54 securedagainst rotation in the housing 48 co-axially with the shaft 47. Formedintegrally with the gear 53 is a second eccentric 56 arranged between apair of abutment faces 44 secured to the traversing frame 43, theeccentric 56, during rotation, pressing alternately on the abutmentfaces 44 to cause reciprocation of the traversing frame.

It will thus be seen that, upon rotation of the shaft 47, the traversingframe 43 together with the rod 39 is reciprocated in the extensions 37,thus causing the saddle members 32 to traverse through the action of thepins 41.

In this example, the internal gear 54 has twenty-one teeth and theexternal gear seventeen teeth, and the combined effect of this ratio andthe motions of the two eccentrics 46 and 56 is to produce a tracepattern (see FIG- URE 3) of the traversing yarn on the surface of thedrafting rollers that varies in amplitude arid point of reversal fromone stroke to another until the driving shaft has madeseventeenrevolutions in one direction during which time the secondeccentric has made four revolutions in the opposite direction. It willbe seen that the pattern repeats only after every seventeenth revolutionof the driving shaft with the result that wear is well spread over thewidth of the drafting rollers.

The spreading of the wear in this manner is enhanced by providing thatthe point of reversal of the traversing yarn on the surface of thedrafting roller is not allowed to occur in the same place more than oncewithin the pattern. This is achieved by providing that the eccentricityof the eccentric 46 is greater than that of the eccentric 56. In thisexample, it is found that satisfactory results are obtained by such adifiference in eccentricity amounting to about A plurality of sectionsof units 24 as described above are arranged along the length of thespinning frame, common driving shafts 52 being connected by suitablecouplings and driven by gearing connecting one end shaft to a suitabledriving member on the spinning frame. Each section is thus complete initself, having its own driving shaft for the various units in thesection and its own traversing gear.

I claim:

1. A drafting apparatus of the kind referred to, in which anintermediate unit is mounted on the apparatus between feed and draftingrollers for slidable movement in a direction transverse to that ofmovement of the roving or the like, and traversing mechanism is providedfor reciprocating the unit, said traversing mechanism comprising astationary internal gear secured to the drafting apparatus, a drivingshaft arranged co-axially with the internal gear, a first eccentricsecured to the driving shaft, an external gear freely mounted on thefirst eccentric and adapted to mesh with the internal gear, at least twoabutments connected to the intermediate unit and a second eccentricmember secured to the external gear and adapted to engage said abutmentsto effect the traversing movement.

2. A drafting apparatus of the kind referred to, in which anintermediate unit is mounted on the apparatus between feed and draftingrollers for slidable movement in a direction transverse to that ofmovement of the roving or the like, and traversing mechanism is providedfor reciprocating the unit, said traversing mechanism comprising astationary internal gear secured to the drafting apparatus, a drivingshaft arranged co-axially with the internal gear, a first eccentricsecured to the driving shaft, an external gear freely mounted on thefirst eccentric and adapted to mesh with the internal gear, at least twoabutments connected to the intermediate unit and a second eccentricmember secured to the external gear and adapted to engage said abutmentsto effect the traversing movement, the eccentricities of the firsteccentric and the second eccentric member being slightly different inmagnitude.

3. A drafting apparatus of the kind referred to, in which anintermediate unit is mounted on the apparatus between feed and draftingrollers for slidable movement in a direction transverse to that ofmovement of the roving or the like, and traversing mechanism is providedfor reciprocating the unit, said traversing mechanism comprising astationary internal gear secured to the drafting appara-- tus, a drivingshaft arranged co-axially with the internal gear, a first eccentricsecured to the driving shaft, an external gear freely mounted on thefirst eccentric and adapted to mesh with the internal gear, at least twoabut-- ments connected to the intermediate unit and a second eccentricmember secured to the external gear and adapted to engage said abutmentsto effect the traversing movement, the eccentricity of the firsteccentric being greater than that of the second eccentric member.

4. A drafting apparatus of the kind referred to, in which anintermediate unit is mounted on the apparatus between feed and draftingrollers for slidable movement in a direction transverse to that ofmovement of the reving or the like, and traversing mechanism is providedfor reciprocating the unit, comprising a series of intermediate unitsmounted on a common supporting member slidab y mounted for traversingmovement in a supporting framework, and wherein the traversing mechanismcomprises a stationary internal gear secured to the drafting apparatus,a driving shaft arranged co-axially with the internal gear, a firsteccentric secured to the driving shaft, an external gear freely mountedon the first eccentric and adapted to mesh with the internal gear, atleast two abutments on the supporting member and a second eccentricmember secured to the external gear and adapted to engage said abutmentsto effect the traversing movement.

5. A drafting apparatus of the kind referred to, in which anintermediate unit is mounted on the apparatus between feed and draftingrollers for slidable movement in a direction transverse to that ofmovement of the roving or the like, and traversing mechanism is providedfor reciprocating the unit, comprising a series of intermediate unitsmounted on a common supporting member slidably mounted for traversingmovement in a supporting framework, and wherein the traversing mechanismcomprises a stationary internal gear secured to the drafting apparatus,a driving shaft arranged co-axially with the internal gear, a firsteccentric secured to the driving shaft, an external gear freely mountedon the first eccentric and adapted to mesh with the internal gear, atleast two abutments on the supporting member and a second eccentricmember secured to the external gear and adapted to engage said abutmentsto effect the traversing movement, the eccentricities of the firsteccentric and the second eccentric member being slightly different inmagnitude.

6. A drafting apparatus of the kind referred to, in which anintermediate unit is mounted on the apparatus between feed and draftingrollers for slidable movement in a direction transverse to that ofmovement of the roving or the like, and traversing mechanism is providedfor reciprocating the unit, comprising a series of intermediate unitsmounted on a common supporting member slidably mounted for traversingmovement in a supporting framework, and wherein the traversing mechanismcomprises a stationary internal gear secured to the drafting apparatus,a driving shaft arranged co-axially with the internal gear, a firsteccentric secured to the driving shaft, an external gear freely mountedon the first eccentric and adapted to mesh with the internal gear, atleast two abutments on the supporting member and a second eccentricmember secured to the external gear and adapted to engage said abutmentsto effect the traversing movement, the eccentricity of the firsteccentric being greater than that of the second eccentric member.

Germany July 9, 1959 Great Britain May 7, 1952

